1. Field of the Invention
The present invention relates to an electrode tip dresser which dresses a pair of electrode tips held in a welding gun for spot welding while minimizing a grinding task inevitably involving formation of swarf.
2. Discussion of the Related Art
There are conventional electrode tip dressers which can dress electrode tips for spot welding while minimizing a grinding task involving formation of swarf. In such conventional electrode tip dressers, a die is used on which a deformed electrode tip is pressed so that the electrode tip is dressed (as disclosed in, for example, Japanese Patent Laid-open Publication Nos. 2004-167535 and 2001-138065).
When an electrode tip is dressed using such an electrode tip dresser, it is possible to reduce the loss of the material of the electrode tip, as compared to traditional methods in which the electrode tip is dressed using a polishing or grinding process. For this reason, such an electrode tip dresser has been advantageously used for an electrode tip, which is used in a spot welding task, in that it is possible to reduce the loss of the material of the electrode tip, and thus, to use the electrode tip for a prolonged period of time.
The electrode tip, which is used in a spot welding task, has a tip section, and a cylindrical shank section. The tip section of the electrode tip has a circular tip surface that contacts a work piece to be welded, and an enlarged diameter portion having a diameter increasing as it extends from the peripheral edge of the tip surface to the shank section. In such an electrode tip, it is important to secure the shape of an angular portion formed at the peripheral edge of the circular tip surface, namely, at the boundary between the tip surface and the enlarged diameter portion, in order to secure the shape and area of the tip surface required for a spot welding task.
For this reason, the electrode tip, which has been deformed after being used in a certain number of welding processes, is pressed on a die at a high pressure in the above-mentioned conventional electrode tip dresser, to plastically deform the tip portion of the electrode tip, and thus, to dress (regenerate) the electrode tip.
However, when dressing of an electrode tip is carried out using the conventional electrode tip dresser, it is necessary to separate the electrode tip from a welding gun. In other words, it is impossible to dress the electrode tip in a state in which the electrode tip is held in the welding gun.